1. Field of the Invention
The present invention relates to a printer for printing image information or the like, and more particularly, to a printer of an optical writing type which carries out a printing operation by irradiating light corresponding to image information or the like from light emitting elements onto printing paper of a photosensitive microcapsule type.
2. Description of the Related Art
A conventional printer head device is structured such that flashing light emitted according to image data by a plurality of light emitting diodes forming a print head formed on a substrate provided on a carriage guided by a carriage guide and reciprocated by a motor is, after the light diameter is decreased by pinholes of a given aperture, irradiated onto printing paper. The light emitting diodes are extremely small. A top portion that emits light and a connection portion formed on a substrate are connected by two bonding conductors. Since the distance from an aperture to the substrate is relatively large so as to prevent the aperture from contacting the light emitting diodes and to prevent the two bonding conductors from short circuiting, the emitted light leaks out from a pinhole of a non-corresponding position of the aperture to affect the image. Further, at the same time, since the distance from the light emitting diodes to the printing paper is large, there is also a problem in that the light energy received on the printing paper is small.
Further, in the conventional printer head device, there is a fear that, due to heat accompanying the flashing light emitted by the light emitting diodes, the temperature of the substrate and the aperture may rise above the melting point of plastic forming the carriage (about 130.degree. C., for example) to melt or change the shape of a substrate supporting portion of the carriage leading to change in the substrate supporting state, and also, that heat irradiation from the aperture may cause color change or color development of the printing paper to degrade the print quality.